Source : WordNet®

tone down
     v 1: deaden (a sound or noise), especially by wrapping [syn: {muffle},
           {mute}, {dull}, {damp}, {dampen}]
     2: make less strong or intense; soften; "Tone down that
        aggressive letter"; "The author finally tamed some of his
        potentially offensive statements" [syn: {moderate}, {tame}]